May 31 Forces of Nature Series: The Weak Nuclear Force

The strong nuclear force is the tight binding of protons and neutrons to a nucleus. It's opposite number, the weak nuclear force, is responsible for radioactive decay. In other words, the atomic nucleus breaking down into smaller nuclei.

Soon after the Big Bang, the four forces of Nature became what we know them to be today. In physics this is called the Quark Epoch. During this period the Universe was filled with a dense hot quark-gluon plasma. The very early Universe was much too hot for neutral atoms to form. The beginning of time was nearly entirely orange in colour in every direction before the expansion cooled the Universe and created "space" for new particles to travel within.

The weak nuclear force can also be called Quantum Flavour Dynamics (QFD) because the quarks within the nucleus decay to become other particles and quarks, or change flavour so to speak.

Over time a neutron can decay into a proton, an electron and an electron antineutrino. The splitting of the atom is known as nuclear fission, not to be confused with nuclear fusion for example the Sun fusing hydrogen to helium.

Nuclear fission plays a crucial role in both nuclear weapons as we touched on last week and the ever controversial nuclear power. When nuclear fission occurs, a nucleus breaks down, produces vast amounts of energy and even emit gamma rays!

So how does nuclear power work? A highly radioactive substance - mainly Uranium, is artificially broken down to release vast amounts of energy. The heat is passed to a working fluid like water, which generates steam, the steam turns a turbine and this gives us electrical power.

Credit : wiring diagram

A kilo of uranium broken down using nuclear fission releases around 3,000,000 times more energy than a kilo of coal burned in a coal powered plant (7.2 × 1013 joules per kilogram of uranium versus 2.4 × 107 joules per kilogram of coal).

The reactor is cooled by water or molten salt to regulate the temperature inside a nuclear power plant. A meltdown occurs whenever the cooling system inside the plant fails and the nuclear fuel continues to burn. We all know of the incidents in Chernobyl and Fukushima.

Interestingly the product that comes out of the funnel of the nuclear reactor is steam. In coal burning, the funnel product contains carbon and carbon dioxide and burns oxygen to keep the coal fires going. Nuclear power can be incredibly efficient given that very little fuel goes a terribly long way. Coal is also running out, is extremely costly is getting more difficult to mine for.

The use of nuclear power will also reduce consumption of oil and fossil fuels. The amount of energy generated by nuclear power has been described in the past as "too cheap to meter". The weak nuclear force for nuclear power, is accelerated and its energy is harnessed for human use.

Unfortunately, the above mentioned nuclear accidents have been detrimental on the nuclear power industry.

Like most other bright ideas such as supersonic flight, wind power, electric cars and robotic surgery, nuclear power frightens us poor humans despite its massive potential for mankind. We don't like change as a species. After all we are just a bunch of apes who recently learned to walk upright.